Generally, a vehicle slipping prevention device means a snow chain engaged in a tire of a vehicle for preventing a slipping of a vehicle when a vehicle runs on an iced road owing to snow. Since it is impossible to use a snow chain on a road having a high possible accident such as on a highway, a special tire such as a snow tire or a spike tire for preventing a slipping is used.
The above vehicle slipping prevention device uses a trapezoid shape chain connected by a cable or an integral type snow chain connected in a block shape by means of urethane. In the integral type vehicle slipping prevention device, when a connection ring or a connection cable is broken and disconnected, the entire fixing force of a vehicle slipping prevention device is lost, and the entire structure of a vehicle slipping prevention device may be separated from the tire. Even when not separated, it is impossible to recycle the same.
In the integral type vehicle slipping prevention device, a woman driver or a weak or disabled driver is not able to easily engage or disengage the device. When a driver meets a sudden snow or icy road, it is impossible to fast engage the device. Since it is needed to engage or disengage the device while moving the vehicle forward or backward, it is impossible to engage or disengage the device on a slanted road.
The integral type vehicle slipping prevention device is generally designed to fit with the tires of a passenger vehicle. In case of a large size bus or a truck able to carry a lot of passenger or freight, since the rear wheels, which transfer a driving force, are made in a form of double wheels (the double wheels are used for reducing a flat accident by distributing the total loads to each wheel). So, the integral type vehicle slipping prevention device has a problem for engaging to a large size vehicle which is equipped with double wheels.
In the integral type vehicle slipping prevention device, it is difficult to engage and disengage the chain. In consideration with a narrow width and small diameter of a double-wheel tire used in a freight transportation vehicle, the vehicle slipping prevention device designed for a passenger car may have a smaller fixing force or a smaller close-contacting force when it is engaged to the tires of a truck or a bus, so that it is impossible to provide an efficient driving force transfer and stop force.
In order to overcome the above problems, a new vehicle slipping prevention device is disclosed, in which a plurality of chains are engaged at a double-wheel tire belonging to a rear wheel structure of a large size truck, while passing through a center (wheel) of a tire.
However, in the above conventional vehicle slipping prevention device, a snow chain is engaged while passing through a wheel, which becomes an engaging surface of a tire, from an outer surface of the tire. So, as the tire rotates, the snow chain rotates along with the same. When a stopping force is continuously transferred to the tire which rotates at a high speed, the stopping force may be eccentrically transferred at one point with no regular interval. Namely, it is focused in one direction, so that it fails to transfer a constant braking force to the double wheels. In this case, when the total weight is focused on the snow chain, the chains may be damaged or disengaged.
In the conventional vehicle slipping prevention device, when a vehicle runs, the weights are focused on the device, and the engaged portions of the fixed snow chains may be disengaged, so that the braking force sharply loses, and a large accident may occur. Namely, the stability of the conventional device is largely decreased.
Since the conventional vehicle slipping prevention device is not provided with a member for maintaining the intervals, a plurality of spikes are directly engaged to the double wheel. When a vehicle runs on a non-uniform ground, the snow chains may be gathered at one side and may be tangled, so that the braking force may be applied in a centrifugal force direction owing to the sudden cornering operation or the vehicle is steered in a certain direction opposite to the direction that the driver steers, so an accident may occur.
In order to overcome the above problems of the conventional device, the same applicant as the present invention disclosed a vehicle slipping prevention device in which a plurality of spikes are connected with the chain and are inserted between the space between the double wheels at regular intervals (Korean patent registration number 10-0526439 (Oct. 28, 2005), and disclosed another vehicle slipping prevention device (Korean patent application number 10-45946 (May 23, 2006)) which improves the problems of the above registration patent.
However, the vehicle slipping prevention device filed by the same applicant as the present invention has the following problems.
Namely, when a vehicle runs, the spikes connected with the chains are inserted into the space between the double tires. A certain engaging member, which is used for engaging the above spikes with a certain tensional force, may be disengaged by means of vibrations occurring when the vehicle runs or by means of a centrifugal force. So, the chain and spikes may be disengaged.
In addition, when a vehicle runs a long distance or runs on a snow road or a unpaved road, a lot of abrasion may occur in the surfaces of the spikes.